Development process

ABSTRACT

THIS INVENTION DESCIBES A PROCESS FOR THE PRODUCTION OF A PHOTOGRAPHIC RECORD WHICH COMPRISES DEVELOPING PHOTOGRAPHIC MATERIAL HAVING A GELATINO SILVER HALIDE EMULSION CONTAINING A DEVELOPABLE SILVER IMAGE IN A SILVER HALIDE DEVELOPING SOLUTION, THE PROCESS BEING CHARACTERISED IN THAT IT IS CARRIED OUT IN THE PRESENCE OF A COMPOUND OF THE FORMULA:   X&lt;(-(3-R1,4-R2,5-R3,6-R4-1,2-PHENYLENE)-N=C(-R)-)   WHERE X REPRESENTS AN OXYGEN, SULPHUR OR SELENIUM ATOM, R REPRESENT A HYDROGEN ATOM OR AN ALKYL OR SUBSTITUTED ALKYL GROUP, AN ARALKYL GROUP, AN ARYL GROUP OR A GROUP SR5 WHERE R5 REPRESENTS A HYDROGEN ATOM OR AN ALKYL OR SUBSTITUTED ALKYL GROUP, AT LEAST ONE OF R1, R2, R3 OR R4 IS A NITRO GROUP AND THE REMAINDER ARE EACH SELECTED FROM A HYDROGEN OR A HALOGEN ATOM, OR AN ALKYL, ARALKYL, ALKOXY, MONO- OR DI-ALKYLAMINO, ACYLAMINO OR A NITRO GROUP.

United States Patent 3,677,761 DEVELOPMENT PROCESS John Colin Brown andRoy Anthony Cheer, Ilford, England, assignors to llford Limited, Ilford,England No Drawing. Filed June 26, 1970. Ser. No. 50,314 Claimspriority, application Great Britain, June 26, 1969, 32,426/ 69 Int. Cl.G03c 1/06, 1/34, 5/30 US. Cl. 96-665 5 Claims ABSTRACT OF THE DISCLOSUREThis invention describes a process for the production of a photographicrecord which comprises developing photographic material having agelatino silver halide emulsion containing a developable silver image ina silver halide developing solution, the process being characterised inthat it is carried out in the presence of a compound of the formula:

This invention relates to the processing of silver halide photographicfilm material and in particular to the processing of photographic filmmaterial under conditions which tend to give rise to a high fog level inthe processed material.

It is usual to include an antifoggant in silver halide photographicdeveloping solutions because the actual development process tends tocause fog in the developed material. The usual antifoggant employed indeveloping solutions is a water-soluble bromide. However under certainconditions it is required to use a stronger antifoggant than bromide andfor this purpose a number of organic antifoggants have been used.

It is the object of the present invention to provide a photographicdevelopment process wherein certain novel autifoggants are used.

According to the present invention therefore there is provided a processfor the production of a photographic record which comprises developingphotographic material having a gelatino silver halide emulsioncontaining a developable silver image in a silver halide developingsolution in the presence of a compound of the general formula:

ice-

where X represents an oxygen, sulphur or selenium atom, R represents ahydrogen atom or an alkyl or substituted alkyl group, an aralkyl group,an aryl group, or a group SR where R represents a hydrogen atom or analkyl or substituted alkyl group, at least one of R R R or R is a nitrogroup and the remainder are each selected from a hydrogen or a halogenatom, or an alkyl, aralkyl, alkoxy, monoor di-alkylamino, acylamino or anitro group.

It is preferred that the compounds of the above formula are presentinitially in the photographic material, most preferably in each silverhalide emulsion layer. This is particularly the case when thephotographic material is to be developed at an elevated temperature. Anexample of a photographic development process which employs an elevatedtemperature, Le. a temperature above 30 C. is the so-called rapid methodof processing X-ray films.

The rapid method comprises developing, washing and fixing the filmmaterial in solutions having an elevated temperature, usually 35 C. orabove. The processing usually is carried out in a processing machinethrough which the photographic material is progressed by a rollersystem. For this reason it is usual to include in the developingsolution a gelatin hardening agent such as glutaraldehyde, in order toprevent the swollen gelatin from being badly marked by the rollers. Ithas been found that such a process wherein the developing solution is atan elevated temperature and comprises a gelatin hardening agent tends tocause excessively high fog levels in photographic material processedtherein. However when the photographic material comprises a compound ofthe formula hereinbefore set forth, the fog level in the developedmaterial is reduced.

According to a particular embodiment of the present invention there isprovided a process for the production of a photographic record whichcomprises developing a photographic material having a gelatino silverhalide emulsion and containing a developable silver salt image at atemperature above 30 C. in a developing solution containing a gelatinhardening agent, the said photographic material containing in at leastone emulsion layer or in a layer adjacent thereto a compound of thegeneral formula hereinbefore defined.

The preferred gelatin hardening agent for use in this process isglutaric dialdehyde (glutaraldehyde) or a compound which comprisesglutaric dialdehyde such as a bisulphite addition compound thereof.

The preferred amount of a compound of the above formula to be present inthe emulsion of the photographic material for use in the process of thepresent invention is from 0.2 to 2 g. per gm. mole of silver halidepresent in the emulsion. It is preferred that a compound of the aboveformula is present in each emulsion layer of the photographic material.This is especially so in the case of X-ray film material wherein anemulsion layer is present on each side of the film support. Thecompounds of the above formula may however be present in a supercoatlayer or in a sub-layer as long as this layer is adjacent to theemulsion layer.

However the compounds of use in the present invention may be present inthe developing solution.

The following example will serve to illustrate the invention.

EXAMPLE In this example compounds which fall within the above definedformula, as set forth in Table I which follows, were used. In Table I,the headings X, R, R R R and R refer to the symbols used in the formulaas hereinbefore set forth.

A sulphur and gold sensitised coarse-grained iodobromide emulsion of thetype suitable for X-ray photography with intensifying screens wasdivided into two parts. To the first portion was added the usual coatingaids and hardening agents. The second portion Was treated similarly butin addition there was added the quantity specified in Table II (whichfollows) of the compound under test, dissolved in alcohol to form a 0.5%solution or dissolved in the requisite quantity of dilute sodiumhydroxide solution. Each emulsion was coated on a flexible support inthe conventional manner. After exposure through a wedge to a lightsource the spectral characteristics of which matched the emission from acalcium tungstate intensifying screen, the samples were processed in aconventional machine designed to process radiographs in a dry-to-drytime of 90 seconds: the development phase of this process was 25 secondsat 40 C. The developing solution used was al-phenyl-3-pyrazolidone/hydroquinone based developing solution whichcomprised g./litre of glutaric dialdehyde. The Table II records the dataof fog, speed at a developed silver density of 1.0 and the averagecontrast over the density range of 0.2 to 2.0 for the control emulsionwith no antifoggant and for the test emulsions containing the citedquantity of antifoggant per gm. mole of silver halide (the densitiesspecified are measured from the fog density level and the speed figuresare relative log speeds).

Quan- Compound tity in Average number mg. Fog Speed contrast It isobserved from this table that the control emulsions showed a high foglevel and low contrast whereas the test emulsion, each containing acompound of the formula as hereinbefore set forth, have a relatively lowfog and a high contrast. These qualities are particularly desired inradiographs.

We claim as our invention:

1. In a process for the production of a photographic record whichcomprises developing imagewise exposed photographic material having agelatino silver halide emulsion containing a developable silver image ina silver halide developing solution, the improvement wherein thedeveloping is carried out in the presence of a compound of the formula:

where X represents an oxygen, sulphur or selenium atom, R represents ahydrogen atom or an alkyl group, an aralkyl group, an aryl group or agroup SR where R represents a hydrogen atom or an alkyl group, at leastone of R R R or R is a nitro group and the remainder are each selectedfrom a hydrogen or a halogen atom, or an alkyl, aralkyl, alkoxy, monoordi-alkylamino, acylamino or a nitro group.

2. A process according to claim 1 wherein said compound in claim 1 ispresent in each silver halide emulsion layer of the photographicmaterial.

3. In a process for the production of a photographic record whichcomprises developing an imagewise exposed photographic material having agelatino silver halide emulsion and containing a developable silver saltimage at a temperature above 30 C., in a developing solution containinga gelatin hardening agent, the improvement wherein the said photographicmaterial contains in at least one emulsion layer or in a layer adjacentthereto a compound of the formula:

where X represents an oxygen, sulphur or selenium atom, R represents ahydrogen atom or an alkyl group, an aralkyl group, an aryl group or agroup SR where R represents a hydrogen atom or an alkyl group, at leastone of R R R or R is a nitro group and the remainder are each selectedfrom a hydrogen or a halogen atom, or an alkyl, aralkyl, alkoxy, monoordi-alkylamino, acylamino or a nitro group.

4. A process according to claim 3 wherein the gelatin hardening agent isglutaraldehyde or a compound which comprises glutaraldehyde.

5. A process according to claim 1 wherein R is hydrogen, methyl, phenylor SCH and R R are hydrogen, N0 or CH at least one or R R being N0References Cited UNITED STATES PATENTS 2,131,038 9/1938 Brooker et a196-109 3,326,681 6/1967 Walworth 96109 3,545,971 12/ 1970 Barnes et a1.9663 FOREIGN PATENTS 960,675 6/ 1964 Great Britain 96-1O9 NORMAN G.TORCHIN, Primary Examiner M. F. KELLEY, Assistant Examiner U.S. Cl. X.R.9695, 109

